//分离自normalize.css
// Forms
// 1. Change font properties to `inherit` in all browsers (opinionated).
// 2. Remove the margin in Firefox and Safari.
button,input,select,textarea {
  font: inherit; //1
  margin: 0; //2
}
// Restore the font weight unset by the previous rule.
optgroup {font-weight: bold;}
// Show the overflow in IE.
// 1. Show the overflow in Edge.
button,
input { //1
  overflow: visible;
}
// Remove the inheritance of text transform in Edge, Firefox, and IE.
// 1. Remove the inheritance of text transform in Firefox.
button,select { //1
  text-transform: none;
}
// 1. Prevent a WebKit bug where (2) destroys native `audio` and `video`
// controls in Android 4.
// 2. Correct the inability to style clickable types in iOS and Safari.
button,html [type="button"], //1
[type="reset"],[type="submit"] {
  -webkit-appearance: button; //2
}
// Remove the inner border and padding in Firefox.
button::-moz-focus-inner,
[type="button"]::-moz-focus-inner,
[type="reset"]::-moz-focus-inner,
[type="submit"]::-moz-focus-inner {
  border-style: none;
  padding: 0;
}
// Restore the focus styles unset by the previous rule.
button:-moz-focusring,
[type="button"]:-moz-focusring,
[type="reset"]:-moz-focusring,
[type="submit"]:-moz-focusring {
  outline: 1px dotted ButtonText;
}
// Change the border, margin, and padding in all browsers (opinionated).
fieldset {
  border: 1px solid #c0c0c0;
  margin: 0 2px;
  padding: 0.35em 0.625em 0.75em;
}
// 1. Correct the text wrapping in Edge and IE.
// 2. Correct the color inheritance from `fieldset` elements in IE.
// 3. Remove the padding so developers are not caught out when they zero out
// `fieldset` elements in all browsers.
legend {
  box-sizing: border-box; //1
  color: inherit; //2
  display: table; //1
  max-width: 100%; //1
  padding: 0; //3
  white-space: normal; //1
}
// Remove the default vertical scrollbar in IE.
textarea {overflow: auto;}
// 1. Add the correct box sizing in IE 10-.
// 2. Remove the padding in IE 10-.
[type="checkbox"],
[type="radio"] {
  box-sizing: border-box; //1
  padding: 0; //2
}
// Correct the cursor style of increment and decrement buttons in Chrome.
[type="number"]::-webkit-inner-spin-button,
[type="number"]::-webkit-outer-spin-button {
  height: auto;
}
// 1. Correct the odd appearance in Chrome and Safari.
// 2. Correct the outline style in Safari.
[type="search"] {
  -webkit-appearance: textfield; //1
  outline-offset: -2px; //2
}
// Remove the inner padding and cancel buttons in Chrome and Safari on OS X.
[type="search"]::-webkit-search-cancel-button,
[type="search"]::-webkit-search-decoration {
  -webkit-appearance: none;
}
// Correct the text style of placeholders in Chrome, Edge, and Safari.
::-webkit-input-placeholder {
  color: inherit;opacity: 0.54;
}
// 1. Correct the inability to style clickable types in iOS and Safari.
// 2. Change font properties to `inherit` in Safari.
::-webkit-file-upload-button {
  -webkit-appearance: button; //1
  font: inherit; //2
}
